New insights in oxidation and disinfection processes – Effect of organic matter and formation of secondary oxidants


Event details

Date 22.05.2024
Hour 13:1514:15
Speaker Prof. Holger Lutze. Since 2020, Prof. Holger Lutze is chair of the department Environmental Analytics and Pollutants at the Technical University of Darmstadt and since 2008 scientific advisor at IWW Water Centre, one of the leading water research institutes in Germany. He received his PhD in chemistry at University Duisburg-Essen (UDE) in 2013, funded by a scholar ship of the Society of Water Chemistry - Division of the German Chemical Society (GDCh) (SWC). From 2013-2020 Holger Lutze was head of the research group oxidative processes at the chair Instrumental Analytical Chemistry (UDE). Holger Lutze also chairs the research committee of SWC with more than 100 members dealing with analytical chemistry, emissions and fate of pollutants as well as water treatment processes. Holger Lutze´s research and teaching activities include fundamentals in oxidative water treatment such as reactions of oxidants with matrix constituents, pollutants and microbial matter but also practice oriented studies e. g., to support planning of wastewater ozonation. He received several awards such as the for his PhD (2015) and for postdoctoral studies (2019) (both from SWC).
Location Online
Category Conferences - Seminars
Event Language English

Oxidative water treatment is a very important step for disinfection and pollutant degradation. Worldwide the most often used oxidant is chlorine as it is easy to apply and a very good disinfectant. However, all oxidation processes change the chemical composition of the water matrix. E.g. reactions of oxidants with organic matter often lead to the formation of undesired by-products but also to further (secondary) oxidizing agents. This largely increases the complexity of these processes as intrinsically formed oxidants themselves can form undesired by-products and have an effect on disinfection and pollutant degradation. The most prominent example is the formation of highly reactive hydroxyl radicals in ozone-based processes which contribute to pollutant degradation. Recent results have shown that the reaction of chlorine dioxide (ClO2) with organic matter forms hypochlorous acid as a secondary oxidant. This results in an additional set of undesired by-products but also effects pollutant degradation and disinfection processes. The intrinsic formation of secondary oxidants is also important for intracellular reactions. The formation of hypochlorous acid in the endoplasm of pathogens may largely increase cell damage and may thus, improve the ClO2 based disinfection process.
These examples show that the natural and bacterial organic matter has far more influence on oxidation processes than a sole consumption of an oxidizing agent. Due to complexity of the NOM-structure these reactions are yet, not well understood. A better understanding of these processes will be become more important in the future, since the quality of water resources is changing, as one of the consequences of climate change.
In the seminar new mechanistic insights of oxidant reactions with natural and bacterial organic matter and the formation of secondary oxidants will be discussed.

Practical information

  • Informed public
  • Free
  • This event is internal


  • Prof. Tamar Kohn

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